In recent years, various light-emitting devices in which plural solid-state light-emitting elements such as light-emitting diodes (LEDs) are mounted on a substrate for use as a light source have come into practical use. Such light emitting devices are widely used, for example, as a matrix display device in which a matrix of plural LEDs emits light selectively to display characters or images, a backlight for a liquid crystal panel of a liquid crystal display device, or the like.
In such a light-emitting device, each of the LEDs mounted on the substrate is covered with a transparent cover member, in most cases. The cover member is used, for example, to protect or seal the LED or to refract, in a desired direction, an optical path of light emitted from the LED.
Heretofore, there has been a proposal of a molding method for forming a lens-shaped cover member for an LED mounted on a substrate. Specifically, the method includes forming a pair of opening holes in the vicinity of the LED mounted on the substrate; and setting, on one surface of the substrate, an upper mold provided with a cavity in a predetermined form of lens for the mounted LED, and on the other surface thereof, a lower mold provided with a different runner serving as a pouring basin corresponding to the cavity. The method includes then injecting a molding liquid resin from the runner provided in the lower mold into the cavity in the form of lens via the opening holes; and subsequently curing the liquid resin, thereby forming the cover member over the LED (for example, refer to Patent Document 1).
Patent Document 1: Japanese Patent Application Laid Open Publication No. 2007-27433